These type brush rings described above are being used to form brushes in most heterogeneous sweeping lorries and brushing machines. The brush rings being used today usually comprise a ring shaped frame part that has been bent to a circumferential shape, when viewed in a perpendicular direction with respect to the longitudinal direction of the brushes, and is usually made of thin sheet iron, the thickness of which is e.g. about 1 mm and in which the brushes have been attached e.g. by means of suitable solidifying attachment mass. These type of brush rings are usually plane shaped, when viewed in the longitudinal direction of the brushes, when the aim is to produce brushes having a particularly good quality.
Those type brush rings, that are partly made of metal, tend to break particularly because of cold conditions, due to stiffening of the brushes. As a result, the sheet iron frame supporting the brush part of the brush ring may open in certain places, in which case bigger or smaller units of brush parts are released from the brush ring. In addition to that, in the type of brush rings described above having metal frames and plastic brushes, that reuse of the same is impossible in practice, because removing of the frame sheet iron from the brushes is not economically justified in practice. That is why these brush rings are removed as a whole to the dumping area, creating a significant waste problem. Furthermore, when brush rings described above, are being used, very strongly built supporting structures must be used, such as space rings made of metal, fastening rings etc., which is why a brush made with these kinds of brush rings becomes disproportionately expensive.
On the other hand from Finnish Patent No. 87977, a brush element is previously known, that is entirely made of plastic based material. The brush elements being produced by the method described in this patent, are plane shaped, when viewed in the longitudinal direction of the brushes, and due to wearing of the brushes, the brushing of the brush formed of the brush rings becomes uncontinuous in the longitudinal direction of the brush particularly in the jointing points of the brush rings. As a result, the brush is not able to fulfil conventional demands, that are needed in certain purposes, because material to be brushed may go through the brush without touching the brushes, in which case the brush must be dismantled and the brush rings of the same replaced.
On the other hand solutions corresponding to a certain extent to the brush ring described above have been presented in documents FI 40453, DE 39 14 745 and FI 2140/70, also, whereby in the two formerly mentioned documents there has been presented a brush ring that extends sidewards in a so called zig-zag style, but in both of which the actual frame part of the brush ring is formed as a metal structure e.g. from injection molded aluminium (FI 40453) or bent sheet iron (DE 39 14 745). Thus neither of the above enables an entirely recyclable and reusable entirety, which fact has a crucial meaning particularly nowadays. Additionally, the type of solutions described above are very complicated, that is why manufacturing costs of the same are disproportionately high. With the type of solutions in question it is not possible to reach an adequate measuring precision, which weakens functioning of the brush formed of the brush rings and shortens its operating time. The solution presented in document FI 2140/70 differs very clearly from the above, which does not describe the frame part and the brush part of the brush ring made of the same recyclable material. In addition to that, in this solution separate metal sockets to be bent in shape are requested for attachment of the brushes to the frame part as well as binding plates placed on both sides of the actual frame part. In this solution the frame part does not either include an essentially circumferential frame part, when viewed in a perpendicular direction with respect to the longitudinal direction of the brushes, but instead an actual rotating center and a circle part connected to the same with radially directed ribs.